Field of the Invention
The invention relates to the field of sealing caps or oversealing caps, and typically aluminium-based or tin-based metal caps. The invention relates particularly to a process for manufacturing these caps.
Metal sealing caps, typically made of aluminium, can be produced as follows:                a drawing press forms deep-drawn blanks from flat blanks that are typically cut by punching a metal coil varnished on both sides, with a typical thickness ranging from 0.21 to 0.25 mm,        the blanks are degreased in a stove at high temperature, typically from 180 to 210° C., for a time ranging from 3 to 5 minutes, so as to remove the drawing lubricant,        the blanks are then lacquer coated over their external surface and are placed in a stove in order to bake the lacquer,        the lacquered blanks are printed on the skirt, typically offset, with a final drying of the inks in a stove,        an overprint varnish is finally applied to the impression so as to protect it, the varnish being dried in a stove,        the blank thus obtained is equipped with a threaded interior plastic insert and/or a seal.        
As regards the metal caps, whether they are sealing caps or oversealing caps, there is a constant need both to reduce the production costs, so that they will not be replaced by other more economical caps produced by different technology and a different material, and to improve the decorations and their service life.
Embodiments of this invention address these two problems.